Aircraft boom control and balancing mechanism



March 1954 T. D. CASTOR ET AL 2,670,913

AIRCRAFT BOOM CONTROL AND BALANCING MECHANISM Filed April 24, 1950 3Sheets-Sheet l INVENTOR. THOMAS DAV/S CAS OR CLIFFOED J LE/SY By WILLIAMA. SANGST'EE ATTORNEYS March 2, 1954 T. D. CASTOR ET AL 2,670,913

AIRCRAFT BOOM CONTROL AND BALANCING MECHANISM Filed April 24, 1950 3Sheets-Sheet 2 JNVENTOR. m AVIS (tasro SANGSTE'E A T TOE/v5 V5 March 2,1954 CASTORI ET AL AIRCRAFT BOOM CONTROL AND BALANCING MECHANISM FiledApril 24 3 Sheets-She INVENTOR. A 3 DA VI 5 (A 5 T F0 o OE L/ l 227 JLE/SY y WILLIAM A SANGSTER W i l ATTORNEYS Patented Mar. 2, 1954AIRCRAFT BOOM CONTROL. AND BALANCENG MECHANISM Thomas Davis Castor andClifford J. Leisy, Seattle, and. William A. Sangster, Mercer Island,Wash, assignors to Boeing Airplane Company, Seattle, Wash, a corporationof Delaware Application April 24, 1950, Serial No. 157,822

21 Claims. 1

This invention pertains to: apparatu intended primarily for transferringfuel from one airplane to another in flight and is directed especiallyto apparatus on the tanker airplane. The apparatus is of the samegeneral type as that disclosedin the co-pending application of Leisy,Serial No. 108,070, filed August 2, 1949.

Both in the present apparatus and in that disclosed in the aforesaidco-pending application, a boom was carried beneath the rear portion ofthe tanker airplane and was controllable for both vertical and lateralswinging of its trailing end so that it could be moved universally forcontact with receiving apparatus on the receiving airplane. In addition,the boom was of telescoping construction so that it could be lengthenedor shortened, as desired, to make contact with the receiving airplane.The boom was hollow, enabling fuel or other material to be transferredthrough the boom from the tanker or supply I airplane to. the receivingairplane, after the boom had been suitably connected to the receivingairplane.

The present invention is utilized in an aircraft interconnecting,material transfer system of this general type, and is directedparticularly to aerodynamic control of the boom both prior to and duringcontact of the aft end of the boom with the receiving airplane.Specifically; it is an object of the present invention to provide aunique aerodynamic control for the boom which will enable itsmanipulation into various positions prior to being connected with thereceiving airplane and which, in addition, will reduce aerodynamicforces on the boom when displaced from a given position, whether beforeor after it has been connected to the receiving airplane.

Especially it is an object to control automatically lair reactionsurfaces while the boom is connected to a receiving airplane so that,despite variations in the relative positions of the. airplanes, whethervertically or laterally, the boom will exert only such forcetransversely of its length on the receivin airplane as may be desired,or on the receiving airplane as the airplanes move relatively.

It is a further object to provide such an automatic control of the boomby operation of its air reaction surfaces, while at the same timepreserving the elfectiveness of the manual control so that the boomoperator may at any time override the automatic operation of the airreaction surfaces to produce a force on the boom acting in any directiontransversely of its length.

will produce no increased lateral force tionate motion. As the- Anadditional object of the invention is gen-- orally to simplify theaerodynamic control mechanism for the boom and the nature andarrangement of the air reaction surfaces themselves.

More specifically, a feature of the invention is to utilize, preferablonly two air reaction surfaces, projecting generally horizontally fromopposite sides of the trailing portion of the boom and having aconsiderable dihedral angle so that an upright control surface isunnecessary. Such control surfaces then fulfill the function of both therudder and the elevators, and may be desi nated ruddevators, the boom.empennage, as a whole, being of the V tail Wpe. c

In employing such a ruddevator type of boom control it is a feature tointerconnect the two ruddevators by balancing mechanism which will pivotthem conjointly relative to the boom so that, as the boom rises orfalls, both ruddevators will be tilted relative to the boom in the samedirection to maintain their angle of attack approximately constantdespite vertical movement of the boom, and which will effect conjointdifferential or opposite pivoting of the ruddevators as the boom swingslaterally. Depending upon the design of the balancing mechanism, theboom may be allowed to float either vertically or laterally at willwithout the empennage exerting any appreciable restoring force except asthe control' surfaces may be moved by the pilot. Alternatively, thecontrol surfaces may be balanced to exert a predetermined amount ofrestoring force when the boom swings vertically out of a given position,or when the boom swings laterally out of a given position, or both.

The balancing mechanism generally is of the parallel motion type,although the proportion of the parts may be selected to give adisproporboom swings vertically relative to the longitudinal axis of thefuselage the balancing mechanism will effect movement of the ruddevatorsrelative to the boom through an angle equal to the angle of boommovement and in a direction such that the chords of the ruddevators willmaintain approximately the sameangle relative to the longitudinal axisof the airplane fuselage. Such movement allows the free-floating of theboom so that the boom motion produced by the ruddevators in a verticaldirection is entirely under the control of the boom operator.

' Alternatively, the motion transmission mechanism may be proportionedso that as the boom swings vertically relative to the airplane fuselagethe angular movement of the ruddevators relative to the boom will beless than the angular movement of the boom itself, to produce arestoring force on the boom tending to return it to the verticalposition from which it was displaced.

Likewise, the balancing control mechanism will turn the ruddevators inopposite directions as the boom swings laterally, so that, for a givenangle of lateral displacement, the ruddevators will be turned throughsuch an angle as will tend to maintain the boom in such laterally swungposition in opposition to the air load on the boom. The proportions ofparts of the mechanism may be selected so that the ruddevators will beturned through a lesser angle for a given lateral angle of boom swingrelative to the central vertical plane of the airplane than is necessaryto offset the air load on the boom, in which case a greater or lesserrestoring force will be exerted on the boom tending to return it to itsinitial position.

By properly designing the balancing mechanism, any degree of restoringforce, either vertically or laterally, may be produced automatically bythe angular adjustment of the ruddevators effected by such mechanism. Itis an important feature of that mechanism, however, that it isintegrated with the manual control mechanism which may be manipulated bythe operator so that control movement of the ruddevators in any degreehe may desire may, at any time, be superimposed upon the automaticregulation of these surfaces.

Further advantages of the particular type of automatic balancingmechanism shown in the accompanying drawings will be pointed out in thefollowing specification.

Figure 1 is a side elevational view of the tail portion of a supplyairplane showing the boom in stored position in full lines and in alowered and extended position in broken lines.

Figure 2 is a rear elevation of the aft fuselage portion of the airplaneshowing the boom in full lines in lowered position.

Figure 3 is a fragmentary side elevational view of the booms trailingend shown in raised position, while Figure 4 is a similar view showingthe boom in slightly lowered position, and Figure 5 is a similar viewshowing the boom in a further lowered position.

Figure 6 is a rear elevational view of the trailing end of the boomdisposed substantially in the central plane of the airplane fuselage,while Figure 7 is a similar view showing the boom swung to port andFigure 8 is a similar view showing the boom swung to starboard.

Figure 9 is a side elevational view taken on line 9-9 of Figure 10 of aportion of the control mechanism integrated with the automatic balancingmechanism, and Figure 10 is a plan view of this mechanism taken on lineIll-40 of Figure 9.

Figure 11 is a somewhat diagrammatic top perspective view of theintegrated control mechanism and automatic balancing mechanism as applied to the boom and its mounting structure.

As has been explained in the aforementioned companion application,Serial No. 108,070, a telescoping boom composed of an outer section Iand a longitudinally reciprocable inner section I0 is used tointerconnect a supply aircraft and a receiving aircraft.

Preferably the outer boom section has its forward end carried by thetrailing end of the supply aircraft and disposed beneath it, such as thefor- Ward end of such 'boom element being pivoted in:

a yoke ill on trunnions 2 l, which yoke, in turn, is

mounted for rotation about an upright axis on a hollow shank 22. Thetrailing end of the boom may thus swing vertically on the trunnions 2|and the trailing end of the boom may swing laterally by turning of theyoke shank 22 in its mountmg.

While vertical swinging of the boom about trunnions 2! may be limited,and lateral swinging of the boom may b limited by restricting turning ofyoke 20, such as by engagement of its cross arms 23 with stops 24, thetrailing end of the boom will have universal movement of consider ableamplitude. Upward movement of the boom will be sufficient to enable itto be secured in the hanger 25 projecting from the tail of the airplanefuselage as shown in Figures 1 and 2. The length of the boom may beadjusted within considerable limits by extension of the inner element l0of the telescoping tube assembly, and when proper contact is made with areceiving airplane the booms trailing end may be connected to suchreceiving airplane by a suitable nozzle H.

In utilization of a boom interconnecting two aircraft for transfer ofmaterial from one to the other, of the type generally described above,two problems arise; first, that of manipulating the trailing end of theboom into the proper position vertically and laterally, to establishcontact with the airplane to be connected to the booms trailing end, andsecond, after such contact has been established, to prevent the boomexerting excessive loads on the aircraft to which its trailing end isattached, produced by relative vertical or lateral movement of theaircraft.

- In thus manipulating the trailing end of the boom prior to connectionof its trailing end with the other aircraft, it is desirable for theboom to have as much inherent stability as possible so that when thecontrols are moved to swing the boom into a particular attitude to itssupporting aircraft, whether vertically or laterally, the boom will tendto remain in that position despite air loads produced on it. A boomhaving these characteristics could be positioned wherever desired withminimum control manipulation by the boom operator. On the other hand,after the trailing end of the boom has been connected to the receivingairplane, it would be preferable for the boom control surfaces to bemoved automatically so that the aerodynamic forces on the boom would bebalanced in every swung position, and consequently the boom would notxert any force on the airplane to which its trailing end is con nected.

Because the desirable characteristics of boomcontrol prior to andsubsequent to the boom coupling operation are diametrically opposite,some compromise between these two types of op eration ordinarily will bepreferable. With the automatic balancing mechanism described below anydesired operation between these two types is possible.

As has been explained in the co-pending application of Leisy, Serial No.108,070, it is preferred that manipulation of the boom, both verticallyand laterally, be accomplished by aerodynamic controls. Preferably theseare in the form of a v tail on the rear portion of the boom composed oftwo combination elevators and rudder- 3, designated ruddevators. Therudder action is accomplished by the horizontal compo-- nents oi thelift forces on these surfaces when the angle of incidence of oneruddevator is increased and that of the other is decreasedsimultaneously. During such movement the changes emarcin the verticalcomponents. of thel ift on the two.- ruddevators occur in. opposite:senses and" approximately balance each other, whereas the horizontalcomponents are additive toward the ruddevator whose angle of incidenceis decreased- Elevational forces ar produced on theboom by tilting bothruddevators simultaneously and equally either to increase or decreasetheir angle of incidence. The desired sheet of the automatic balancingmechanism is illustrated in Figures 3, 4 and 5.. Figure 4 shows the boominclined Slightly downward, such as might be the attitude produced bythe balance between the weight of the boom and the load of the airon. itcaused. by movement of the airplane. The ruddevators are at zero angleof attack, but, because of their shape, produce some aerodynamic lift toassist the air load in raising the boom.

If the boom should be subjected to a sudden updraft of air its trailingend might be displaced into the position shown in Figure3, but theauto.- maticv balancing mechanismv would rotate the ruddevators throughan angle approximately equal to the angle of boom displacement so thatthey would still have zero angle of attack. Conversely, if the boomshouldbe subjected to a sudden downward air load, so that it wasdisplaced into the position shown in Figure 5, the angle of incidence ofthe ruddevators would be reduced, again to maintain their angle ofattack unchanged. In neither case, therefore, would the ruddevatorsexert any restoring force to move the boom back to the position. ofFigure 4. On th v contrary, upon cessation of the upward. air load ordownward air load, the normal air load would be restored, which would bethe only automatic force acting to return the boom to the position ofFigure 4. For that reason. the boom might tend to hunt considerablyunless its return to th position of Figure 4 were expedited by the boomoperator swinging the ruddevators to produce a restoring force. Thisaction would be the same, of course,if the displacement were caused bysome peculiar air load whether on the boom itself or on an aircraftconnected to the trailing end of the boom.

Figures 6, 7 and 8 illustrate the balancing adjustments of theruddcvators necessary to prevent the production of an aerodynamicrestoring force, or greatlyreduc it, if a side air load. should swingthe boom laterally from its. central position. The effect of swingingthe trailing end ofthe boom to port from the position of Figure 6. tothat of Figure 7 is to increase the angle of attack of the portruddevator and to decrease the angle of attack of the starboardruddevator. Consequently, the composite effect of such changes in anglor attack is for the ruddcvators to produce an aerodynamic force tendingto;

swing the. trailing end of the boom back to the central position. Inorder to eliminate suchv effects of the ruddevators, the automaticbalancing mechanism is controlled by rotation of the yoke 20 as itswings to decrease the angle of incidence of the outboard ruddevator andto increase the angle of incidence of the inboard ruddevator so that no,or at least less, restoring force will be produced by the ruddevators.

It will be evident that thi change inangle of incidence of the tworuddevators should be accomplished simultaneously and equally in degree,and that such change must increase pro gressively as the displacementangle of the boom increases in order to avoid production oi a re storingaerodynamic force, or to maintain 0011- stant therelationship betweensuch'a. restoration force and the angle of boom swing. Thu in Fig-- ure7 the angle of incidence of the port: ruddevator is. decreased and thangle of incidence of the starboard ruddevator is increased as the boomis swungto port, and, conversely, in Figure 8 the angle of incidence ofthe starboard ruddevator is decreased, and of the port ruddevator isincreased as th boom is swung to starboard.

If the ruddevators are thus swung differentially to. eliminateaerodynamic restoring force.

produced by them, the only restoring force which will act on the boom isthe air load on the boom itselt. Indeed, even such air load may, if desired, be counteracted by providing sufilcient alteration in the angleof incidence of the ruddevators. On the contrary, if some aerodynamicrestoring force is desired, the change in anglev of incidence of theruddevators will be less than that required to-eliminate completely theaerodynamic restoring force- Having in mind the type of ruddevatorcontrol andbalancing action desired, attention is directed t'o-Figures9, 10 and 11, illustrating the manually" operated. control mechanismintegrated with the automatic balancing mechanism to adjust the angle ofincidence of the ru-ddevators conjointly, either in the same directionfor elevational con trol, or in opposite directions for lateral controlof the aerodynamic forces acting on the boom.

Figure 11 shows in broken lines the boom I carryingthe ruddevators 3 anditself carried by the yoke 26. The mechanism operable to adjust theangle of incidence of the ruddevators is shown diagrammaticallysuperimposed upon this structure, but it will be understood thatordinarily such operating mechanism will be. suitably housed: and may bearranged in any convenient fashion capable of effecting the operationshereinafter described The ruddevator operating mechanism includes twopulleys 36 mounted coaxially with the respective ruddevators, androtatable to turn the ruddevators relative to the boom I for alteringtheir angles of incidence. Over these pulleys pass cables it whichcontact guide pulleys 32 carried. by and arranged conveniently along thelength of the boom I to guide the cables 3| for passage about pulleys 33journaled on the oppositelegs" of the yoke 20.

'. Pulleys 33 are double, one part of each receiving a cable 3! and the.other part receivinga cable.

34? extendingfrom the pulley 33 up through thetubular shank 22 of theyoke 20 into the interior of the airplane. The cables 34 are guided byguide pulleys :35 carried by the yoke at opposite ends of its shank todirect the cables 34 through it. from pulleys 3.3, and from the upperend of such.

spindle around drive pulleys 36. These "drive 7 mililgy's arerotatcdthrough diiiercntial gear-as semblies 31 which are moved both byautomatic lie-dancing mechanism and by manual control mechanism Theautomatic balancing mechanism connected with. the respectivedifierential gear devices 37 effects the balancing action of theruddevators during iateral swinging of the boom. The central gear of thediiferential gear mechanism rotatcson a shaft 39 jcurnaled in thehousing 40' on an axis. disposed perpendicular to the axis of drivepulleys 35 and of the shafts $9 for the gears of the difle'rentialgearing not secured to the pulleys 36.. The. automaticsbalancingmechanism includes leversv e secured. to the housing 40 'oi'the'. 7 difierential zgear: mechanism, which. levers: are

connected by links 4| to the opposite arms of the yokecrossbar 23, beingsecured to such crossbar by pivots 42. This crossbar has additionalapertures 43 and 44, for example, in which the pivots 42 of links 41 maybe engaged to vary the degree of automatic balancing effect produced bythe mechanism, as will be explained.

The control mechanism for the ruddevators includes pulleys secured uponshafts 39. About these pulleys extend cables 53 which are secured toquadrants 5| carried by coaxial shafts 52. These shafts carry oppositegears of a further differential gearing arrangement 53, the intermediategear 54 of which carries the control column 55. The housing of thisdifferential gearing has a stop arm 55 secured to it to limit theconjoint rotation of shafts 52 in the same direction. This stop armengages stationary stops 5? and 58 shown in Figure 9. Other stops 59,disposed at opposite sides of control column 55, limits its tilting foreffecting rotation of gear 54.

The balancing movement of the ruddevators effected during verticalswinging of the boom as illustrated Figures 3, 4 and 5, is accomplishedby the pulleys 30, cables 3! and pulleys 33. If the control column 55 isnot moved, and if the yoke 23 is not turned by lateral swinging of theboom, pulleys 33 will be held stationary by cables 34 and pulleys 36which would not rotate. If, therefore, pulleys 33 are the same size aspulleys 30, the wrap of cable 3| around the upper portion of pulleys 33as the boom l swings downward will cause both pulleys so to rotatecounterclockwise, as viewed in Figure 11, to decrease the angle ofincidence of the ruddevators 3. Conversely, if the boom 1 swings upwardthe cables 3! will be wrapped around the lower portions of pulleys 33sufficiently to cause clockwise turning of pulleys 3B and hence anincrease in the angle of incidence of the ruddevators relative to theboom. 1f pulleys 33 are smaller than pulleys 30, the angular movement ofthe ruddevators will be less than the angle of swing of the boom I, andconsequently, some aerodynamic restoring force will. be produced by theruddevators, the amount depending upon the relative sizes of pulleys 30and 33.

To superimpose upon this parallel movement balancing mechanism anelevational control movement of the ruddevators, it is merely necessaryto. rotate pulleys 33 simultaneously in the same direction and to thesame degree, the direction of rotation determining whether the angle ofincidence of the ruddevators will be increased or decreased. Suchmovement of pulleys 33 may be accomplished by fore and aft movement ofthe control column 55. If this control column is moved forward, that is,to the left in Figure 11, diiferential gearing 53 will be rotated as aunit to turn both quadrants 5i counterclockwise which will cause cable50 to rotate both drive pulleys 5 clockwise. Since the casing of thedifferential gearings 3! will remain stationary, pulleys'36 in turn willbe rotated counterclockwise, which will cause cables 34 to rotatepulleys 33 clockwise. Driven by cables 3|, pulleys 33 also will berotated clockwise to increase the angle of incidence of both ruddevators3 equal amounts. An aerodynamic lift will thus be produced on thetrailing portion of boom l to swing it upward.

Conversely, if the control column 55 is swung rearward, that is, to theright in Figure 11, the rotative direction of quadrants 5! and the otherpulleys mentioned above will be reversed, so that the angle of incidenceof ruddevators 3 will be' decreased to produce an aerodynamic force forswinging the boom downward. Obviously, such control movement of column55 may be accomplished without in any way interfering with the automaticvertical balancing function of pulleys 39 and 33 and cables 3|.

The automatic lateral balancing function is accomplished by the lateralbalancing mechanism rotating pulleys 33 in opposite direction and inequal amounts as the boom swings laterally while control column 55 isnot swung laterally to rotate gear 55. The mechanism for accomplishingsuch lateral balancing action includes cables 34, guide puileys 35,pulleys 33 and differential gearing 31, which elements are common to theelevational control mechanism described. Assuming that the controlcolumn 55 is held stationary, however, pulleys 5 will not be rotated, sothat shafts 39 remain stationary. As the boom swings to starboard, forexample, which would swing the yoke 20 carrying it in a counterclockwisedirection, as

viewed from above in Figures 10 and 11, the up-- per link 4| in Figure11 would be shifted lengthwise to the left to swing its lever 4clockwise, whereas the lower link M would be shifted lengthwise to theright to swing its lever A counterclockwise.

Bearing in mind that shafts 39 are held stationary, the clockwiseswinging of upper lever 3 in Figure 11 will rotate the upper pulley 36in that figure clockwise, whereas the swinging of the lower lever 4 in acounterclockwise direction will turn its differential gearing casing 49to rotate the lower pulley 35 counterclockwise. Thus the clockwiserotation of the upper pulley 36 will rotate the left pulley 33counterclockwise, and the counterclockwise rotation of the lower pulley35 will rotate the right pulley 33 clockwise. correspondingly, the upperpulley 30 will be turned counterclockwise to decrease the angle ofincidence of its, ruddevator, and the lower pulley 35 will be turnedclockwise to increase the angle of incidence of its ruddevator.

The degree of such conjoint but opposite angular displacements ofruddevators 3 will, of course, depend upon the degree of rotation ofarms 4, pulleys 36 and pulleys 33 for a given swing of boom l andcorresponding rotation of yoke 25. For a given turn of this yoke theangular displacement of arms l may be varied by altering the length oflever arm of crossarm 23 acting on link All, or the effective length ofarms 4. Thus the locations of pivots 42 may be shifted from thepositions shown in Figure 11 to holes 43 or, as shown in Figure 10, toholes 53 to increase correspondingly the angular movement of arms B andthe change in angle of incidence of the ruddevators corresponding to agiven angular displacement of the boom. If, when the pivots 42 of linksM are engaged in holes M, the angle of incidence of the ruddevators ischanged sufliciently to eliminate entirely the restoring aerodynamicforce, a small restorative force will be produced if the link pivots areengaged in holes 43. and a still greater restorative force will beproduced when the links are pivoted at the innermost holes of arms 23,as shown in Figure 11.

While in describing the automatic lateral balancing operation it hasbeen assumed that pulleys 5 remained stationary, it will be evident thatthey could have been rotated simultaneouslythrough equal degrees at anytime by fore and aft movement of the control column 55 without aesrosisinterfering with the differential movement :of pulleys 35, accomplishedby rotation of lever arms 1. In addition, lateral control movement ofthe control stick 55 may be superimposed upon the lateral balancingaction of the mechanism described. is accomplished efiecting rotation ofpulleys d in opposite directions instead of both in the same direction.

Assuming that control stick 55 is fore and aft, but only laterally,turned to rotate one quadrant *5! in one direction and the otherquadrant 5 in the opposite-direction. This, in turn, will rotate pulleyst in opposite directions. If the differential gear casings it are notrotated in opposite directions. if the gear casings -41! are also beingrotated in omaosi'te direetions, the opposite rotations of pulleys 35will either be augmented or red-razed so that their rotation becomes thealgebraic Sblln of pulleys '5 and arms 5. Such movements of pulleys 35will be transmitted through cables 3 3 to pulleys 33, which turn willeffect corresponding changes in the angles of incidence of ruddevators3.

It will be seen, therefore, that the automatic balancing control forelevational movement of the boom, the automatic balancing control foriatera'l swinging or" the boom, and the manual control mechanism foreirect-ing voluntarily both -elevational and lateral swin of the boomare all interconnected at all times, so that the changes in angles ofincidence of the ruddevators not swung gear =54 will he the 'integrationof the action of the control mechanism and the :two automatic balancingmechanisms to produce the desired boom swinging action characteristics.Vertical manual con- 'trol of the boom is limited in opposite directionsby the s o a Iii once-ems thestops 5i and whereas lateral controlincrement .is limited by the control column 55 engaging stops 515.lateral swinging movement of the boom is limited positively byencasement ,o'f crossarm 23 with stops 2'4.

With mechanism described, therefore, the desired automatic balancing .ofthe .boom may be accomplished without in the .leastrestricting thepositive control of theoperator over boom movement, although the limitsof such control and (of boom swinging are established by convenientistopmechanism.

Weclaimasour invention:

1. Mechanism for interconnecting aircraft in ifiight comprising a ,stifiboom, means andireely pivotingsaid boom directly to arr-aircraft intrailing attitude iorswi g n relative to such ,aircratt both upward anddownward and laterally, air reaction -,control surfaces :mounted.movably on .said boom, and balancing mechanism interconnectingtheaircrait and said air reaction control surfaces and opera leautomatically {to more said reaction surfaces relative to {said boom assaid boom swings relative to the aircraft.

2. .Mechanism :for interconnecting aircraft in flight -.comprising .aboom, means supporting said .boom :from an aircraft in trailin attitude.for swinging relative :to such :aircraft, :ruddeyators 'cpivoted,respectively, 1m :opnosite sides :of .said

Frbonm in iDOSitiQIlS projecting outwardly afromz-op- 'posite .sidesthereof and upwardly :suiliciently to ,-exert .a substantialathwartships aerodynamic force, and ibalancing mechanism interconnecting:the aircraft :and said ruddevators and operable being rotated, pulleys35 will *be of the rotation univers ly .1

zautomaticallyito :turnsaid ruddevators oppositely 1E5 T of the beam orcomposite vertical 10 relative to said boom as said boom swingslaterally-relative to the aircraft.

3. Mechanism for interconnecting aircraftfl-ight comprising a boom,means supporting said boom from an aircraft in trailing attitudegforlateral swinging relative :to such aircraft, an air reaction.controlsurface mounted moi/ably on said boom and movable :to produce anathwartshins force on said boom, and balancing mechanism in.-terccnnecting the aircraft and said air reaction control surface andoperabie automatically to move said air reaction control surfacerelative to said boom, as said Eboom swings relati-ye to the aircrait-laterall-y out .of a plane :paraliel to the flight path of theaircraft.

e. The mechanism defined in claim 3, and control means operablevoluntarily to change the angle of attack of the air reactioncontrol-surface any laterally swung position of the :boom.

:5. Mechanism for interconnecting .aircrLaf-t flight comprising a boom,means supporting said boom from an aircraft in trailing attitude forswinging laterally relative to such aircraft, rndelevators pivotedrespectively on opposite sides .of

said boom, and balancing mechanism interconnesting said aircraft andsaid ruddevators and operable automatically as said boom swings relativeto the aircraft laterally out of a plane -.par.alle1 to the flight pathof the aircraft to turn 3531131 rudde-vatorsinaoppositedirections.

.6. The mechanism defined in claim 55, and manual control means operablevoluntarily to modify the action of the balancing mechanism to effectturning of the iruddevators in opposite directions in varying degrees,thereby superimposing a voluntary control action on the balancing actionof saidibalancing mechanism.

7. The mechanism defined in claimlfi, including differential gearingmechanism having one gear operativel yconnected to a ruddevator, asecond gear operatively connected to the balancing mechanism, and athird gear operatively .connected to the manual control means to eliectrotation of said first gear in response to integrated movement :of saidsecond and third gears.

'8. Mechanism for interconnecting aircraft flight comprising a boom,means supporting said boom from an aircraft in trailing attitude forswinging relative to such aircraft, both vertically and laterally,ruddevators, pivoted respectively on opposite sides of said boom, andbalancing mechanism interconnecting said aircraft and :said ruddevatorsand operable automatically as said boom swings vertically relative tothe aircraft to turn said ruddevators relative to said boom in the samedirection, and author operable automaticallyas said boom swingslaterally relative to .the aircraft to "turn said ruddevat-ors inopposite directions.

'9. The mechanism defined in claim 8, and manual control means operable-voluntarily to modify the action of the balancing mechanism to move thruddevators todifferent degrees-tor effecting voluntary vertical orlateral swinging and lateral swinging of 'the boom.

10. Mechanism "for interconnecting aircraft in 'flight comprising aboom, means supporting said i'boom -from an 'aircraft in trailingattitude for swinging relative to said aircraft, 'both vertically andlaterally, air reaction control surfaces mounted *mova'bly on said boom,manual control means operable -voluntarily to eiiect movement of said'air reaction control surfaces, and means operatively interconnecting-=said manual control 'trol surface aircraft for rotation about turn theruddevators direction to maintain substantially constant angle of attackas the boom swings vertically,

means and said air reaction control surfaces, and

including balancing mechanism interposed be tween said manual controlmeans and said air reaction control surfaces operable to move said airreaction control surfaces relative to the aircraft as said boom swingsvertically and laterally relative to the aircraft, and controllable bysaid manual control means to modify the movement of said air reactioncontrol surfaces.

11. The mechanism defined in claim 10, in which the balancing mechanismincludes parallel motion mechanism for controlling movement of the airreaction control surfaces automatically during vertical swinging of theboom relative to the aircraft.

12. The mechanism defined in claim 10, in which the balancing mechanismincludes differential gearing operable by lateral swinging movement ofthe boom to effect movement of the air reaction control surfaces as theboom swings laterally.

13. Mechanism for interconnecting aircraft in flight comprising a boom,a yoke journaled in the aircraft for rotation about an upright axis, and

supporting said boom in trailing attitude for lateral swinging relativeto the aircraft, an air reaction control surface mounted movably on saidboom and movable to produce an athwartships force on said boom, andbalancing mechanism carried by said aircraft operatively connected tosaid yoke and operatively connected to said air reaction controlsurface, and operable automatically by rotation of said yoke relative tothe aircraft as said boom swings laterally relative to the aircraft tomove said air reaction conrelativ to said boom in an amountcorresponding to the rotation of said yoke relative to the aircraft.

14. The mechanism defined in claim 13, and adjustable means operativelyconnecting the balancing means and the yoke and adjustable to vary themovement of the balancing means effected by a given rotation of theyoke.

defined in claim 13, and differential gearing means incorporated in thebalancing mechanism, and link means connected to the yoke and operableto move said differential gearing means.

16. The mechanism defined in claim 15, and manual control meansconnected to the differential gearing means and operable to effectmovement thereof for integration with the movement thereof effected byrotation of the yoke.

17. Mechanism for interconnecting aircraft in flight comprising a boom,a yoke journaled in the an upright axis and supporting said boom intrailing attitude for swinging both laterally and vertically relative tothe aircraft, ruddevators pivoted respectively on opposite sides of saidboom, parallel motion balancing mechanism interconnecting said yoke andthe ruddevators and operable automatically to simultaneously in the same15. The mechanism lateral balancing mechanism including two differentialgearing devices, link means interconnecting said respective differentialgearing devices and said yoke, and means interconnecting saiddifferential gearing devices and said parallel motion balancingmechanism and operable automatically by movement of said differentialgearing devices, effected by rotation of said yoke relative to theaircraft as the boom swings laterally relative to the aircraft actingthrough said 'link means, to effect conjoint rotation of saidruddevators in opposite directions to decrease the angle of attack ofthe outboard ruddevator and to increase the angle of attack of theinboard ruddevator, and control means operable to move said differentialgearing devices similarly to turn said ruddevators conjointly in thesame direction and further operable to move said differential gearingdevices oppositely to turn said ruddevators conjointly in oppositedirections, for effecting voluntary vertical and lateral swinging ofsaid boom, respectively.

18. Mechanism for interconnecting aircraft in flight comprising a stififboom, means universally and freely pivoting said boom directly to anaircraft in trailing attitude for swinging relative to such aircraftboth upward and downward and laterally, air reaction control surfacesmounted movably on said boom, and balancing mechanism interconnectingthe aircraft and said air reaction control surfaces and operableautomatically, a said boom swings in a given direc tion relative to theaircraft, to move said air reaction surfaces relative to said boom indirections for producing aerodynamic forces on said boom opposing suchboom swinging.

19. Mechanism for interconnecting aircraft in flight comprising a boom,means supporting said boom from an aircraft in trailing attitude forswinging relative to such aircraft, ruddevators pivoted, respectively,on opposite sides of said boom in positions projecting outwardly fromopposite sides thereof and upwardly sufficiently to exert a substantialathwartships aerodynamic force, and balancing mechanism interconnectingthe aircraft and said ruddevators and operable automatically, as saidboom swings laterally relative to the aircraft, to turn said ruddevatorsoppositely relative to said boom in directions producing additiveathwartships forces acting toward the central longitudinal plane of theaircraft.

20. Mechanism for interconnecting aircraft in flight comprising a boom,means supporting said boom from an aircraft in trailing attitude forswinging upward and downward and laterally relative to such aircraft,two air reaction control surfaces mounted pivotally on said boom inpositions projecting upwardly and outwardly from opposite sides thereof,means operable to rotate said control surfaces one in one direction andthe other in the opposite direction to efiect lateral movement of thetrailing end of said boom, and balancing mechanism interconnecting theaircraft and said air reaction control surfaces and operableautomatically to rotate said air reaction surfaces in the same directionrelative to said boom as said boom swings upward or downward relative tothe aircraft.

21. Mechanism for interconnecting aircraft in flight comprising a boom,means freely pivoting said boom on an aircraft in trailing attitude forswinging upward and downward relative to such aircraft, air reactioncontrol surfaces projecting respectively from opposite sides of saidboom and pivoted to turn about athwartships axes,

13 means operable to efiect voluntary swinging of said boom relative tosuch aircraft including control means operable to change the angle ofattack of the air reaction control surfaces and thereby effect suchmovement of said boom relative to 5 such aircraft.

THOMAS DAVIS CASTOR. CLIFFORD J. LEISY. WILLIAM A. SANGS'I'ER.

References Cited in the file of this patent UNITED STATES PATENTS ameDate Number 14 Name Date Roche Jan. 6, 1914 Torkelson Apr. 21, 1931Zimmerman Aug. 11, 1931 Moran Mar. 8, 1932 Weaver July 19, 1932 MuellerJuly 5, 1938 Akerman July 26, 1938 Van Waveren Apr. 30, 1940 DornierOct. 7, 1941 Ryan et a1 June 3, 1947

